This invention relates to a baler for forming round bales of crop material, and more particularly to a system for detecting a differential in bale diameter during formation of a round bale within a bale-forming chamber defined by the round baler.
Balers for forming round bales of agricultural crop material typically have a crop pick-up arrangement which supplies crop material to the bale-forming chamber through a crop inlet. Prior to baling, crop material is typically cut and placed in windrows on the ground, and the windrows are then fed by the pick-up arrangement into the bale-forming chamber. In order to form a bale having a uniform diameter throughout its length, the operator of the round baler must constantly alter the position of the baler relative to the windrow, to ensure that the crop material is supplied to different areas of the bale-forming chamber through the crop inlet. Commonly, operators have a tendency to supply a greater amount of crop material to the central area of the bale-forming chamber than to the end areas, resulting in a bale having an oblong shape.
Various bale shape monitors have been developed in an effort to overcome this problem. Examples of prior art bale shape monitors are shown in Gaeddert et al U.S. Pat. No. 4,224,867 issued Sep. 30, 1980. The '867 patent discloses a bale shape monitor which senses the tension in the endmost baler belts. Since a belt in an area of lesser bale diameter will have a lesser degree of tension than a belt in an area of greater bale diameter, the presence of a differential in belt tension is used to indicate a differential in bale diameter. While this type of bale shape monitor indicates a differential in bale diameter, it is disadvantageous in that it relies upon sensing the condition of certain baler components in order to sense a differential in bale diameter, i.e. the sensing of bale diameter differential is indirect. Furthermore, this involves dedicated components which must be assembled to the baler within tight tolerances in order to obtain accurate information pertaining to a differential in bale diameter.
It is an object of the present invention to provide a bale shape monitoring or sensing system which is located within the bale-forming chamber and which provides direct detection of a differential in bale diameter. It is a further object of the invention to provide a bale shape monitoring or sensing system which is adapted to be employed in combination with a preexisting component of the baler, which is normally located within the bale-forming chamber of the baler. Yet another object of the invention is to provide a bale shape monitoring or sensing system which is accurate and sensitive, and which is capable of promptly providing a signal to an operator so as to enable the operator to reposition the baler so as to correct the shape of the bale. A still further object of the invention is to provide such a bale shape monitoring or sensing system which is relatively simple in its components, construction and operation, yet which is capable of providing prompt and accurate signal to alert the operator of a differential in bale diameter.
In accordance with the invention, a bale shape sensor or monitor for a round baler having a bale-forming chamber includes a movable member located within the bale-forming chamber and at least a pair of spaced apart rollers rotatably mounted to the movable member. The movable member is adapted to move in response to growth of the bale within the bale-forming chamber. The rollers are arranged to rotate in response to contact with the baler belts as the bale rotates within the bale-forming chamber. A sensor arrangement is associated with the rollers, for sensing rotation of the rollers and for outputting a signal when at least one of the rollers ceases to rotate or rotates at a speed below a predetermined threshold, to indicate a differential in bale diameter in the vicinity of the rollers. In a preferred form, the movable member is in the form of a laterally rigid frame member which extends across the bale-forming chamber, and the rollers are preferably engaged with the endmost belts to indicate a differential in bale diameter at the ends of the bale. The movable member may be configured so as to move outwardly in response to contact between the movable member and the bale at a location between the rollers. The movable member may be in the form of a frame assembly having a series of bale-starting fingers or the like, which extend through the spaces between the belts and engage the crop material during initial formation of the bale, to assist in directing the crop material during formation of the bale. The bale shape sensor or monitor further includes an indicator which is interconnected with the sensor arrangement, for providing a sensory output to the operator indicating the area of the bale having a lesser diameter. The operator then controls the position of the baler so as to supply material to the crop inlet at the lesser diameter area of the bale.
The invention further contemplates an improvement in a round baler and a method of detecting a differential in bale diameter during bale formation, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.